Why are the settings not showing up?
This issue is likely caused by pinning the data-block's properties after an object was deleted. The property tabs can be restored by unpinning.



Description of the pin functionality in the manual:


  By toggling on the pin icon to the right, Blender can be told to
  display in that editor only the currently shown data-block’s
  properties, disregarding further selection changes. Toggle off that
  pin to switch back to default behavior, showing active data-block’s
  properties.


Alternatively you can also uncheck Load UI when opening a project through File > Open in Blender, which ignores all UI settings stored in the project file. This can be helpful for example when loading a project from older versions of Blender with a different UI layout.